The present invention relates to antimicrobial formulations. More specifically, the present invention relates to antimicrobial formulations which are highly effective against a broad range of microorganisms such as bacteria, fungi, yeasts, molds, protozoan, and viruses while substantially less irritating to the skin than previous formulations. The antimicrobial formulations of the present invention can be applied directly to the skin or can be applied to a variety of substances or carriers such as cellulosic webs, nonwoven structures, and textile-based materials, and are particularly useful in products such as facial and bath tissues, wet wipes, diapers, incontinence products, feminine care products, and wound management products.
Today, many consumers are demanding that personal health care products such as wet wipes, diapers, etc. have the ability to not only provide their intended function, but also eliminate to a large extent problem microorganisms, such as rhinoviruses, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis, for example, while not harming the consumer""s health. To meet this demand, antimicrobial agents have been incorporated into a wide range of consumer products, such as wet wipes, to combat both transient and resident bacteria on skin. Antimicrobial-containing products are currently marketed in many forms such as lotions, deodorant soaps, hard surface cleaners, wet wipes, and surgical disinfectants.
Many products that contain antimicrobial agents, however, are harsh or irritating to the skin due to the nature of the chemicals utilized to provide the antimicrobial effect. For example, some hard surface cleaners and surgical disinfectants utilize high levels of alcohol and/or surfactants which have been repeatedly shown to dry out and irritate skin tissues. Other wet wipes currently available utilize harsh cationic surfactants without the addition of acids. Although the surfactant is capable of penetrating and killing many types of bacteria, it is very irritating and harsh to the skin.
Many antimicrobial-containing products utilize an organic acid in combination with an anionic or cationic surfactant as antimicrobial agents. Although some organic acids can safely be utilized in products to control microorganisms without the presence of surfactants, most products incorporating only an organic acid have a low efficacy against bacteria and fungi unless used at very high concentrations. At very high concentrations, these acids can make the ultimate product uneconomical and can even raise skin irritation concerns.
Both anionic and cationic surfactants have, for some time, been known to impart certain benefits to antimicrobial formulations and compositions. Under certain conditions, surfactants exhibit high antimicrobial activity against a broad range of bacteria and other microbes. Although not completely understood, it appears that the surfactants are highly effective in disrupting or disorganizing the outer structure of the microbes allowing direct access into the microbes by other components. As mentioned earlier, the addition of surfactants to antimicrobial formulations is not, however, completely free from problems as many surfactants can be highly irritating to skin.
As such, a need continues to exist for antimicrobial formulations which can be utilized in various products such as wet wipes and facial tissue. Ideally, the antimicrobial formulations and products containing the formulations would gently clean and deodorize the skin while significantly reducing the amount of active microbial agents, while at the same time not drying out or irritating the skin.
The present invention provides an antimicrobial formulation, a method of using the antimicrobial formulation, and products incorporating an antimicrobial formulation. The antimicrobial formulation of the present invention is highly effective against numerous bacteria, fungi, yeasts, molds, protozoan and viruses yet is gentle to the skin of the user. It has been discovered that when one or more proton donating agents such as organic or inorganic acids are combined with an alkyl phosphate anionic surfactant comprised at least partially of a mono alkyl phosphate, numerous microorganisms are inactivated. Further, the antimicrobial formulations of the present invention are essentially free from an antimicrobial active. A suitable liquid carrier such as water or a woven or non woven substrate is easily used in combination with the antimicrobial formulations of the present invention to inactivate numerous microorganisms. Notwithstanding their high antimicrobial activity, the formulations and products of the present invention have been found to be substantially non-irritating to the skin of the user. Such a combination of highly effective antimicrobial formulations without skin irritation is greatly needed. The present invention can be used to produce products which may be applied directly to the skin such as soaps, lotions or wet-wipes containing the antimicrobial formulations. Alternatively, the present invention can be used to produce products such as bath or facial tissues containing the antimicrobial formulations.
Briefly, therefore, the present invention is directed to a wet wipe comprising a fibrous sheet material and an antimicrobial cleansing solution. The solution is essentially free of an antimicrobial active and comprises a proton donating agent and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate.
The invention is further directed to a wet wipe comprising a fibrous sheet material and an antimicrobial cleansing solution. The solution is essentially free of an antimicrobial active and comprises a carboxylic acid and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate. The carboxylic acid comprises from about 0.01 weight percent to about 10 weight percent of the total weight of the solution and the alkyl phosphate anionic surfactant comprises from about 0.01 weight percent to about 10 weight percent of the total weight of the solution.
The invention is further directed to a wet wipe comprising a fibrous sheet material and an antimicrobial cleansing solution. The solution is essentially free of an antimicrobial active and comprises a carboxylic acid and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate. The antimicrobial cleansing solution has a pH of from about 2 to about 7.
The invention is further directed to a wet wipe comprising a fibrous sheet material and an antimicrobial cleansing solution. The solution comprises a carboxylic acid and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate, and has a pH of from about 2 to about 3.
The invention is further directed to an antimicrobial formulation for direct application to human skin. The formulation is essentially free of an antimicrobial active and comprises a proton donating agent and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate.
The invention is further directed to an antimicrobial formulation for direct application to human skin. The formulation is essentially free of an antimicrobial active and comprises a proton donating agent and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate. The solution has a pH of from about 2 to about 7.
The invention is further directed to an antimicrobial formulation for direct application to human skin. The formulation comprises a proton donating agent and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate. The solution has a pH of from about 2 to about 3.
The invention is further directed to a product comprising a substrate and an antimicrobial solution. The solution is essentially free of an antimicrobial agent and is comprised of at least about 2 percent of the total dry weight of the substrate of a proton donating agent and from about 0.05 weight percent to about 5 weight percent of the total dry weight of the substrate of an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate.
The invention is further directed to a product comprising a substrate and an antimicrobial solution. The solution is essentially free of an antimicrobial active an is comprised of a proton donating agent and an alkyl phosphate anionic surfactant which includes a mono alkyl phosphate.
Other objects and features of this invention will be in part apparent and in part pointed out hereinafter.